Conventional sources for generating mid-infrared light include quantum cascade lasers, frequency comb sources, and conventional incandescent sources. However, each of these sources has significant limitations. For example, quantum cascade lasers require high power consumption and only provide a limited bandwidth. See, for example, Y. Liu, J. et al., Development of Low Power Consumption DFB Quantum Cascade Lasers, IEEE Photonics Technol. Lett. 27 (2015) 2335-2338; G. Wysocki, et al., Spectroscopic trace-gas sensor with rapidly scanned wavelengths of a pulsed quantum cascade laser for in situ NO monitoring of industrial exhaust systems, Appl. Phys. B. 80 (2005) 617-625; and B. S. Williams, et al., Terahertz quantum-cascade lasers, Nat. Photonics. 1 (2007) 517-525. Frequency comb sources similarly require high power consumption and require nonlinear materials. See, for example, T. Ideguchi, et al., Adaptive real-time dual-comb spectroscopy, Nat. Commun. 5 (2014) 3375. On the other hand, conventional incandescent sources of the type used in incandescent lamps provide inefficient, isotropic emission. See, for example, J. Hodgkinson, et al., Non-dispersive infra-red (NDIR) measurement of carbon dioxide at 4.2 μm in a compact and optically efficient sensor, Sens. Actuators B Chem. 186 (2013) 580-588.
Thermal sources (or black bodies) cans serve as mid-IR emitters; however, these sources are low efficiency and emit in all directions.
Improved mid-infrared sources are desired that provide a high optical output with a minimal input electrical power and that address the limitations of the conventional mid-infrared light sources. The invention described herein addresses these needs in the art.